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818 West Diamond Avenue - Third Floor, Gaithersburg, MD 20878 Phone: (301) 670-4784 Fax: (301) 670-9187 Email: info@gl.com

Website: http://www.gl.com 1

Long Term Evolution (LTE)

Protocol Analyzer

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The LTE (Long Term Evolution) protocol standard was developed as an enhancement to existing Universal Mobile

Telecommunications System (UMTS) to provide users enhanced mobile Internet access.

The evolved Universal Mobile Telecommunications Service (UMTS) terrestrial Radio Access Network (RAN), abbreviated as E-

UTRAN, is also known as LTE.

Although an evolution of UMTS (UMTS uses wideband code-division multiple access (WCDMA) for transmitting signals), the LTE

air interface is a completely new system based on orthogonal frequency-division multiple access (OFDMA) in the downlink and

single-carrier frequency-division multiple access (SC-FDMA) (DFTS-FDMA) in the uplink that efficiently supports multi-antenna

technologies (MIMO).

This robust feature is useful when handling the varying propagation conditions seen in mobile radio. In MIMO techniques, either

multiple antennas can transmit the same data stream to improve data-transmission reliability or different antennas can transmit

different data streams simultaneously to increase throughput.

Another significant feature of LTE is its high bandwidth—up to 20 MHz. Because the usable bandwidth is scalable, LTE can also

operate in the existing 5-MHz UMTS frequency bands, or in even smaller bands.

Introduction

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LTE Network Diagram

LTE standard is progressing as a part of 3rd

Generation Partnership Project (3GPP). The Evolved

Packet System (EPS) standardized by 3GPP is divided

into a radio access network known as the E-UTRAN

and a core network known as the Evolved Packet Core

(EPC).

The E-UTRAN consists of eNodeBs, which provide

the radio interface toward the user equipment. The

eNodeBs are interconnected with each other via the

IP-based X2 interface and toward the Evolved Packet

Core (EPC) via the IP-based S1 interfaces.

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GL’s LTE analyzer

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Main FeaturesFollowing are some of the main features of LTE Analyzer.

• Supported Interfaces - S1, S3, S4, S5 (or S8), S6a, S10, S11, S13 and X2 interfaces

• Supports capturing, decoding and performing various test measurements

• Displays summary, detail, hex-dump, summary and statistics views.

• Detail View displays decodes of a user-selected frame from the Summary View.

• Statistics View displays statistics based on frame count, byte count, frames/sec, bytes/sec etc for

the entire captured data.

• Hex dump View displays raw data as a hexadecimal and ASCII octet dump.

• Search and filtering capabilities.

GL’s LTE Analyzer

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Main Features• Exports Summary View information to a comma delimited file for subsequent import into a database or spreadsheet.

• Capability to export detailed decode information to an ASCII file.

• Remote monitoring capability using GL's Network Surveillance System.

• Additional features supported by Offline LTE Analyzer

➢ Trace files for analysis can be loaded through simple command-line arguments.

➢ Multiple trace files can be loaded simultaneously with different GUI instances for offline analysis

GL’s LTE Analyzer

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Protocol Stack

• Decode and analyze full LTE protocol stack.

• Test eNodeB or UE over S1, S3, S4, S5 (or S8), S6a, S10,

S11, S13 and X2 interfaces of the LTE network.

• The protocols supported for decoding across all these

interfaces are NAS, S1AP, X2AP, eGTP, GTP-U, Diameter,

SCTP, UDP, TCP, and IP.

LTE Protocol

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Supported Protocols

LTE Protocol

Supported

Protocols

Standard / Specification Used

SCTP RFC 2960

S1AP 3GPP TS 36.413 V9.0.0

X2AP 3GPP TS 36.423 V9.0.0

eGTP 3GPP TS 29.274 V8.0.0

NAS 3GPP TS 24.301 V9.0.0

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Supported Interfaces and Protocols

• GL's LTE analyzer can capture and decoding various interfaces i.e. S1, S3, S4, S5 (or S8), S6a, S10, S11, S13 and X2 interfaces

of the LTE network. The protocols supported for decoding across all these interfaces are NAS, S1AP, X2AP, eGTP, Diameter,

SCTP, UDP, TCP, IP.

GL’s LTE Analyzer

• S1 Interface

• S3 Interface

• S4 Interface

• S5 Interface

• S8 Interface

• S10 Interface

• S11 Interface

• S6a Interface

• S13 Interface

• X2 Interface

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Supported Interfaces and Protocols (Cont.…)

S1 Interface

• S1-U - Reference point between E-UTRAN and Serving GW for

the per bearer user plane tunnelling and inter eNodeB path

switching during handover.

• S1-MME - Reference point for the control plane protocol between

E-UTRAN and Mobility Management Entity (MME). The MME is

responsible for authentication and critical management for mobile

devices

GL’s LTE Analyzer

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Supported Interfaces and Protocols (Cont.…)

• S3 Interface

➢ It enables user and bearer information exchange for inter 3GPP access network mobility in

idle and/or active state.

• S4 Interface

➢ It provides related control and mobility support between GPRS Core and the 3GPP Anchor function

of Serving GW. In addition, if Direct Tunnel is not established, it provides the user plane tunneling.

• S5 Interface

➢ It provides user plane tunneling and tunnel management between Serving GW and PDN GW.

➢ It is used for Serving GW relocation due to UE mobility and if the Serving GW needs to connect

to a non-collocated PDN GW for the required PDN connectivity.

• S8 Interface

➢ Inter-PLMN reference point providing user and control plane between the Serving GW in the

VPLMN and the PDN GW in the HPLMN. S8 is the inter PLMN variant of S5.

• S10 Interface

➢ Reference point between MMEs for MME relocation and MME to MME information transfer.

GL’s LTE analyzer

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Supported Interfaces and Protocols (Cont…)

• S11 Interface

➢ Reference point between MME and Serving GW

GL’s LTE analyzer

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Supported Interfaces and Protocols (Cont…)

• S6a Interface

➢ It enables transfer of subscription and authentication

data for authenticating/authorizing user access to the

evolved system (AAA interface) between MME and HSS.

• S13 Interface

➢ It enables UE identity check procedure between MME

and EIR

GL’s LTE analyzer

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Supported Interfaces and Protocols (Cont…)

• X2 Interface

➢ Interface between eNodeBs supports load

management and handover coordination between

eNodeBs.

GL’s LTE analyzer

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Real-time Analysis

Default panes - summary, detail, and hex

dump of the frame data views

Optional panes – statistics and call trace views

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Real-time Capture Filter

Real-time Analysis...

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Decode View of LTE Protocol

The detail decode view of LTE call displays the following:

• MAC Layer

• IP Layer

• UDP Layer

• eGTP Layer

• S1AP Layer

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Call Detail ViewLTE Protocol

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Statistics View

LTE Protocol

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INI Decode Options

• Provides options to select eGTP Release 8 or eGTP Release 9

• Identifies the SCTP protocol payload identifier for S1AP, and X2AP

LTE Protocol

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Thank You !